import React, { Component } from 'react'

import './index.css'

export default class Footer extends Component {

    handleCheckAll = (event) => {
        this.props.checkAllTodo(event.target.checked);
    }

    //清除已完成的回调
    handleClearAllDone = () => {
        this.props.clearAllDone();
    }

    render() {

        const {todos} = this.props;

        //已完成的个数
        const doneCount = todos.reduce((pre, current)=>{
            return pre + (current.done ? 1 : 0);
        }, 0);
        //总数
        const total = todos.length;

        return (
            <div>
                <div className="todo-footer">
                    <label>
                    <input type="checkbox" onChange={this.handleCheckAll} checked={doneCount===total && total !==0 ? true : false}/>
                    </label>
                    <span>
                    <span>已完成{doneCount}</span> / 全部{total}
                    </span>
                    <button onClick={this.handleClearAllDone} className="btn btn-danger">清除已完成任务</button>
                </div>
            </div>
        )
    }
}
